It’s been a wonderful summer in Berlin, filled with warm days and enough rain to keep everyone happy. Although we haven’t posted in a long time, our foraging excursions are still thriving on our botanical curiosity and are prodding us into the lush green spaces in and around the city. Today we will focus on a classic foraging activity that has deep cultural roots in Germany and Northern Europe, namely picking wild blueberries.

In Germany, picking mushrooms, nuts and berries is an exciting pastime for many nature lovers. Indeed, local laws guarantee the right to gather small amounts of nuts, mushrooms and berries in the forests surrounding Berlin. Still, picking European blueberries (Vaccinium myrtillum), or Heidelbeeren as they are known in German, is viewed with suspicion due to widespread but irrational fears of echinococcal disease. Known as the “Fuchsbandwurm” in German, this nasty tapeworm lives in foxes, mice, dogs and unlucky humans. A faulty belief that tapeworm eggs from wandering foxes stick to the surface of low-hanging berries and infect hapless foragers persists even among educated German foragers. Dear readers, this means only one thing: more blueberries for us and all informed, intrepid foragers around Berlin! Blueberry season is now coming to an end but at its height in late July the only limiting factor for the novice forager is the slow picking process. To solve this problem, clever Northern Europeans invented what is known in German as the Heidelbeerkamm or the blueberry comb which, true to its name, greatly reduces the effort of actually picking the berries by hand. Still, if improperly used the comb can damage the shrubs and might make it easy to go overboard in terms of quantities of berries picked. Wild blueberries around Berlin do look similar to American species, but there are crucial differences to keep in mind when foraging in the woods. For example, if you are used to picking northern highbush blueberries (Vaccinium corymbosum) in the eastern United States you may completely miss the blueberries growing all over the forests around Berlin: they are much shorter and lower to the ground than their American counterparts!

By now everyone knows that blueberries belong to the exclusive, but abused category of “superfoods”. European blueberries have the same health benefits as their cultivated relatives with the additional benefit of tasting a lot better. They are chock-full of antioxidants and, in particular, contain higher concentrations of anthocyanin than other type of berries. For a thorough review of the medicinal properties of the European blueberry please see here.

European blueberries prefer highly acidic soil and the sandy soil of the coniferous forests of Barnim (north of Berlin) provides an ideal habitat for their growth. Our favorite spots are in the forests next to Birkenwerder and Bernau (on the S1 line). The blueberry shrubs often create dense patches that cover large parts of the forests. They are quite common in the area, so if you hurry up there may still be some berries hanging!

Not long ago, the memory of chestnut trees was deeply rooted in the consciousness of rural communities around the Mediterranean. Known as sweet chestnut (Castanea sativa), the tree likely spread by hand from the Balkans and Asia Minor to other parts of Europe. It thrived in mountainous areas, where chestnuts were readily accepted as means to self-sufficiency by otherwise isolated communities. The American chestnut (Castanea dentata) served a similar function in the Appalachians, before it fell prey to an Asian fungus that put an end to the tree’s dominance in the forests of the Southeastern United States. In Corsica, the chestnut is firmly established in the island’s culinary traditions which impressively features chestnut beer. Likewise in Sardinia, as well as other parts of Italy, chestnuts have become an integral part of the country’s rich culinary tapestry.

Berlin is home to thousands of horse chestnuts (Aesculus hippocastanum) which casual observers may confuse with the lonely occurrences of sweet chestnut trees in parks and streets. Although the horse chestnuts do resemble the delicacy found in outdoor Christmas markets – roasted marroni – they are, in fact, mildly poisonous to both humans and horses. Take a look at the leaves and you will see that these trees have very different features. Once you’ve discovered the differences, you will never mistake horse chestnuts for the “real” chestnut again!

Despite its geographic adaptability and relative hardiness, the sweet chestnut is a paradoxically fragile creature. Once dormant, the tree can withstand temperatures of -20 degrees Celsius; on the other hand, a late spring or early fall frost can easily cause irreparable damage. Chestnuts prefer a moist, humid environment but well-drained soils. Prolonged periods of rain can stress the tree and, if drainage is not adequate, many specimens will drown. In Germany, as well as other parts of Northern Europe, sweet chestnuts were historically managed as coppice because their tall, straight suckers make perfect poles for growing hops. Unfortunately, Berlin lies slightly above the sweet chestnut’s northern limit of fruit production, which means that yields are low and erratic. Looking for and finding sweet chestnuts in Berlin is a reward all in itself, but is compounded by the rarity of such a find. Platforms like mundraub.org are quite helpful in indicating potential locations, as is our berlin plants map and your own happy wanderings around the city.

In a classic example of plant blindness, we kept missing a sweet chestnut tree on Schönfließer Straße next to Arnimplatz even though we frequently walk by there on our way to Con Calma – one of our favorite coffee shops in the area. This year the burrs looked promisingly full but once they fell to the ground, we were disappointed to see small and shriveled chestnuts inside. We did not fare better with an older duo of sweet chestnut trees in Volkspark Humboldhain despite their bountiful appearance. Refusing to give up our fat chestnut dreams, we pressed south toward Treptower Park where we spent a sunny afternoon wandering along the Spree River. Even there, despite a number of both young and old chestnut trees, the spiny burrs were full of disappointingly shriveled nuts. With some luck and tenacity we were able to find a single small but fat chestnut – the one featured in our photo. Perhaps some of our readers have had better luck?

Rivers, brooks and streams have served as fundamental cornerstones of most ancient civilizations, and many urban dwellers today are familiar with canals or waterways, whether natural or man-made. Plant life flourishes along rivers; the earliest “urban” foragers likely considered river banks as places of plenty. As mentioned earlier, the current natural features of the Northern European Lowlands were determined by the retrieval of glaciers, thus making the presence of water abundant. In terms of Berlin’s aquatic attractions, the Panke is at first sight unimpressive: a rerouted and mostly canalized rivulet less than thirty kilometers long, whose slow and meager current comes to a near standstill at some places along its route. It is hard to imagine that in the 19th century the Panke was home to many watermills, or that its waters were once used to brew beer.

We have come to know the Panke through many of our walks along its banks. As the river flows through Wedding and its namesake Pankow, it is only a short walk away from where we live and always provides us with a botanical adventure. Although we have encountered many interesting plant species along the Panke, today we briefly focus on one plant which most of you are familiar with and which is characteristic of wetlands.

Cattails are known the world over, and their characteristic brown flower spikes are hard to miss in the late summer and fall. Berlin has at least two species of wild growing cattails, Common Cattail (Typha latifolia) and Lesser Bullrush (Typha angustifolia). If you take a walk along the Panke, you are eventually bound to come across a colony of cattails and might think you have found an urban foraging treasure trove. The praises of cattails as an edible food have been sung for millennia by many cultures. It seems that nearly all parts of the plants are edible when harvested at the appropriate times. Certainly, the young shoots are edible in the spring, and if you like to get your hands dirty the starchy rhizomes are also edible at this time. Many other parts of the plant are delicious including the inner part of the stalk, the base of the leaves, and even the yellow pollen which apparently makes for a great pancake mix.

However, other uses for cattails are particularly interesting and useful, especially in view of the darker side of industrialism and its disastrous effects on the Panke. The industrial runoff severely polluted the Panke, which consequently became locally known as Stinky Panke. In the past couple of decades there have been major efforts to rehabilitate the river and the results are already promising. So what do cattails have to do with all this? Well, it just so happens that cattails have the ability to absorb contaminants and pollutants from water, in particular arsenic. This is a process known as phytoremediation, and cattails are a poster child for this type of organic water filtration system. While this is great news for the environment, it should definitely make you think twice before harversting cattails from the Panke!

Lately our wanderings have taken us further north in the city, following the Panke River in search of interesting plants, new foraging grounds, and a better understanding of the natural history that has shaped the area. The underlying landscape found here, like much of the Brandenburg area, was fundamentaly determined by the slow movement of glaciers whose watery fingerprints dotted this sandy, infertile part of the North European Plain with lakes and bogs. Were it not for human intervention, the area would be covered by ancient woodlands, a glimpse of which can be seen in the beech forest of the Schorfheide-Chorin Biosphere Reserve northeast of Berlin. Human presence has reshaped the landscape in unexpected ways, from artificial hills created with war rubble to modern green spaces in the form of carefully designed urban parks. It is in one such green space, namely Bürgerpark in Pankow, where we found the plant that we decided to write about today.

Japanese quince (Chaenomeles speciosa), a spiny shrub native to eastern Asia, reached Europe in the late 18th century and became widely grown as an ornamental plant with striking early spring flowers. Its popularity among European gardeners is easy to understand: the Japanese quince not only has aesthetic appeal but is also a frost-hardy plant that can be horticulturally trained in a number of ways, from serving as a thorny hedge or showy espalier to being potted and grown as a bonsai. For the urban forager, Japanese quince fruits are a welcome addition to the fall harvest. The hard but intensily fragrant pomes ripen in late October and resemble miniature quince (Cydonia oblonga) fruits. The spicy scent of the small fruit promises more than what its astringent taste can offer the hungry forager, but cooking these fruits will quickly get rid of their undesirable tartness. The fact that they are naturally high in pectin content also makes them perfect for jams and jellies. But before you relegate the fruit to the realm of exotica preserves and gardening minutiae, consider its nontrivial medicinal history: Japanese quince has traditionally been used as an anti-inflamatory agent for joint problems and as a general health stimulant. Today, its therapeutic propertires are being investigated in relation to Parkinson’s disease.

In Berlin, Japanese quince is found in parks or hedges around the city, and the characteristic yellow fruits make it easy to identify in the fall. Feel free to use our Berlin Plants map to see where we found them. There is also one location marked on Mundraub, although it is right next to a busy road and hence not suitable for foraging.

A few posts ago we featured the split personality of the European yew: lowly hedge yet powerful, magnificent tree. Today we focus on wolfberry (Lycium barbarum or the closely related Lycium chinense), a hedge plant in Berlin whose double life illustrates the slow-shifting cultural landscape of food. Although the Lycium barbarum is native to both Asia and southeastern Europe, it was first introduced into the UK in the 18th century by Archibald Campbell, an enthusiastic gardener and the 3rd Duke of Argyll (hence another common name for the plant is Duke of Argyll’s tea tree). From here on, the sprawling bush has grown wild in hedgerows or has been used sporadically around Europe as a wind barrier. The characteristic flower betrays its membership in the infamous Nightshade family, and the mature ovoid red berries suspiciously resemble the toxic Amara Dulcis (Solanum dulcamara) fruits. This is most likely why the ripe berries were regarded as poisonous and wolfberry has primarily been valued for its menial hedging habits. In Germany, the toxicity of the plant was investigated in the late 19th century in a doctoral dissertation published in Erlangen. The thesis claimed that Lycium spp. contain pupil-dilating substances, a hallmark of nightshade plants such as Belladonna (Atropa belladonna). As a result, wolfberry fruits were not considered edible until their recent introduction into health food markets as the much awaited panacea from the Far East: Goji berries.

Goji berries have a long, distinguished history in traditional Chinese medicine, from being used to improve vision, cure infertility and dry cough to loftier claims of extending longevity. The berries are consumed in a variety of ways: eaten raw or consumed as fresh juice, wine or tea. The dried berries are often featured in soups. When goji berries were “introduced” in Europe, they were accompanied by incredible medical claims of fighting cancer, and preventing premature aging and memory loss. Regardless of the validity of these medical claims, the berries are chock full of vitamins, minerals and antioxidants. Such treasures come with a heavy price tag; you can expect to pay a minimum of 20 euros per kilogram of dried goji berries in most organic health food stores in Berlin. Meanwhile, among German plant aficionados, an atmosphere of confusion ensues as many find it hard to believe that wolfberry, which is considered an invasive weed, is the source of goji berries. Well, dear reader, rest assured! You can gather goji berries all over Berlin, and they are not toxic (for a recent article on the pharmacology of goji berries see here). However, care must be taken not to mistake the plant for the toxic Amara Dulcis. There is also a potential risk of drug interaction when consuming goji berries, in particular with blood thinners such as Warfarin.

We found wolfberry shrubs along the northern side of the S-bahn ring, west of Schönhauser Alle. All the berries were already gone (as you can see in a picture below) and we were quite disappointed, thinking we would have to wait another year for the harvest. On a whim of the moment, we decided to explore a bit further west in Wedding, looking for interesting plants and keeping our eyes open for goji berries as we walked along the small Panke River. As you can tell from the pictures, our optimism was handsomely rewarded by a bowl full of goji berries! The raw berries are somewhat of an acquired taste, as the initial sweetness of the fruit is followed by a potent, lingering bitterness. We are therefore drying the harvested berries (which should reduce the bitterness) and plan on using them in soups and teas!

In our wish to extend the warmth of summer a little longer, we’ve decided to feature a herbaceous plant whose little yellow flowers dotted the city throughout the summer. If you look around carefully, you can still find a few late bloomers along the sidewalks and railroad tracks! The first frost is just around the corner so this is your last chance to see the pretty little flower before the winter sets in.

Greater Celandine (Chelidonium majus) has an illustrious history that reaches back to antiquity, and it never fails to impress any hands-on observers who quickly discover that a broken stem excretes an incredibly bright orange latex. This latex is loaded with useful toxins and, in alternative medicine, is used to get rid of warts (much like fig latex). In European herbalism, celandine also has a long history of use against liver and gallbladder ailments.

In recent years, celandine has become better known in connection with its possible cancer-fighting properties. In fact, the drug Ukrain reportedly uses compounds from celandine to fight several types of cancer including lung, kidney, breast, pancreatic, and skin cancer. Still, the drug remains controversial and is not approved for use in the US or in most European countries (although celandine is on the Commission E – Germany’s regulatory agency for herbs – list of approved herbs).

Bornholmer Strasse runs through our neighborhood as it heads west to the famous Bösebrücke (the first border crossing that opened when the Berlin Wall fell in 1989). Like other street names in the area, it is distinctively Scandinavian. The Danish island of Bornholm – among other places around the Baltic sea – is home to the Swedish Whitebeam (Sorbus intermedia), a medium-sized tree that is frequently featured in landscape architechture. Swedish Whitebeam and the two other Sorbus species mentioned below line both sides of Paul-Robeson-Strasse just west of Arminplatz (see our Berlin Plants map). The bright red Sorbus berries announce their presence in mid-summer and last well into November. When harvested at the correct time and properly cooked, all Sorbus fruits on Paul-Robeson-Strasse are edible, although their sometimes bitter or mealy taste is best tempered in jams.

Rowan (Sorbus aucuparia), sometimes called Mountain Ash, has a distinguished history as a tree with magical and medicinal properties, in addition to having fruits that were traditionally used in jellies to accompany game meats. They are best harvested after the first frost (see bletting) and used for making spirits or jams. The mashed and sieved fruit can be used to flavor bread dough and the dried fruit can provide a sour snack or flavoring for tea. The fresh fruit eaten in large quantities can upset the stomach, although it is hard to imagine anyone enjoying the bitterness of the fresh fruit for more than a few berries! Rowan fruit contains vitamin C and is the source of sorbic acid, a preservative you may have noticed on food labels.

Common Whitebeam (Sorbus aria) is known as “Mehlbeere” (flour berry) in Germany, a name best understood when eating the dry, mealy berries of the tree. Like Rowan, whitebeam fruits are generally harvested after the first frost and their preparation and use is very similar to Rowan fruits, although their taste is quite different. Tea made from the fresh berries has been used as a general stomach regulator: used for both loose bowels and constipation. The bitter seeds contain low levels of cyanogenic glycosides similar to what is found in apples, cherries and other fruit seeds, hence they are best avoided.

The Sorbus genus comprises a large variety of species; for more information and interesting trivia, take a look at this blog which is devoted entirely to Sorbus trees!

This past week we have been visiting our favourite aunt in Southern France, and have decided to report on some of the beautiful plants, which we’ve been observing during our frequent walks through the Provence. We hope that our readers will tolerate this geographical detour in our blog and trust that you will find something of interest here – otherwise you are welcome to leave us angry comments😉

Although the Provence is often associated with lavender, any wanderer who ventures into the uncultivated countryside will likely first cross paths with thyme (Thymus vulgaris). The small, herbaceous plant is visually unassuming but very dominant in the olfactory landscape of the Mediterranean maquis. Thyme is fundamental to much of the cuisine of Southern Europe, but it also has a long history of medicinal use – among other things – as an antiseptic and antifungal remedy.

Blue Stonecrop (Sedum reflexum) is another common plant which thrives in the dry climate and poor, rocky soil of Southern France. Like most other Sedum plants, in addition to being visually captivating, Blue Stonecrop is also edible. The leaves can be eaten raw in salads and sandwiches or cooked in soups and have a pleasant, but slightly astringent taste. Sedum plants are also used as sturdy, drought-resistant plants in ornamental landscaping as well as in green roof architecture (for example in New York).

Wild asparagus (Asparagus acutifolius) is a native plant of the Mediterranean Basin. Unlike the wild asparagus of Euell Gibbons, this plant needs no stalking as it grows bountifully just about everywhere in the Provence. In the spring, the young shoots of the plant are considered a delicacy worthy only of serious gourmands since the taste is considered particularly intense. In Italy, the parboiled young shoots are sautéed with onions to make delicious frittata or used as a main ingredient in mouth-watering risotto.

Terebinth (Pistacia terebinthus) is a small tree typical of the gentle slopes of the Provence and the Mediterranean region. The resin from the tree has been used since antiquity as a source of turpentine, hence its other common name, turpentine tree. Throughout the southeastern Mediterranean, terebinth fruits and young shoots have been used as flavouring in bread making, brandy and other culinary adventures (see for example this article on the use of terebinth in Crete). Unfortunately, all of the terebinth trees that we saw during our explorations of the Provence were diseased: a gall-inducing aphid preys on this particular species of Pistacia tree throughout the Mediterranean.

Unless confronted with more elaborate topiary forms, the urbanite is only passively aware of the importance of hedges in landscape architecture. Yet, the usual simplicity of hedge rows serves as a clear visual reference for the boundary between wild and cultivated, or public and private spaces. In short, hedges serve as green borders whether functional (see the Great Hedge of India) or aesthetic. In Berlin, the European Yew (Taxus baccata) is commonly employed as a hedge, although this particular use of the yew grossly understates its historical and medicinal significance.

The yew is one of the most ancient trees of Europe and a number of living specimens are thought to be thousands of years old (for example, the Fortingall Yew in Scotland). The earliest known wooden artifact is a yew spear, and the flexibility and durability of the yew tree have made it a preferred material for weapon-making throughout the centuries. The yew achieved notoriety in military history as the source of the renowned English longbow, the long range and deadly force of which helped win many battles for the English.

In the 1960s, compounds from the bark of the Pacific Yew (Taxus brevifolia) were discovered to have anti-cancer properties. Today, Taxol (or paclitaxel) is considered an effective drug in the fight against ovarian cancer. However, before the active compound was successfully synthesized, the bark of four grown yew trees was only enough to treat a single cancer patient, so it is no surprise that the Pacific Yew quickly became an endangered species.

All parts of the yew (also known as “Tree of Death”) are extremely toxic, and concoctions made from the leaves and seeds have been used to commit suicide since ancient times. Yet, as any fearless forager knows, the flesh of the red berries (called arils) is edible and deliciously sweet. Care must be taken to eat only the berry and to completely avoid the seed in the middle! In Germany, the yew has been named “Giftpflanze des Jahres 2011” (poisonous plant of the year, 2011) in order to create awareness of its toxicity and possible fatalities due to its ingestion.

The nightshade family is a prolific provider of natural poisons, a byproduct of the plants’ alkaloid arsenal in their fight for survival against insects and would-be predators. Despite our intimate relationship at the dinner table with many members of this family, some nighshades have earned a fearsome reputation as porters of mad dreams, and in some cases even death.

Jimson weed (Datura stramonium) is an annual shrub that is widespread in warm and temperate climates around the world. In Berlin, it often grows in wastelands, although it can easily be encountered along sidewalks or in parks. During late summer and fall, jimson weed is particularly easy to identify because of its unusual spike-covered fruit and its elongated, attractive white flowers.

All cultures that have come in contact with Datura spp. have quickly become aware of the effects of its consumption. In smaller doses, the plant has the effect of causing sleep and stupor; yet upon further use hallucinations and delirium set in. Historically Datura spp. has been used, among other things, in shamanistic rituals and initiation rites, but the possibility for recreational use and abuse has always been present. Recently, art historian David Bellingham has argued that Botticelli’s “Venus and Mars” depicts the gods in the throes of Datura induced delirium. However not everyone is convinced, since the painting was likely completed before Columbus sailed for the New World and a number of botanists believe that Datura stramonium is native to the Americas.

In Haiti, Jimson weed has the nefarious reputation of being used in zombification, which is considered a crime under the Haitian Penal Code. As far-fetched as it sounds, Datura stramonium is thought to be used to revive corpses and induce the psychological stupor characteristic of slow-moving zombies (see this article for more). Hence Jimson weed’s local Haitian name: “zombie cucumber.”